Question

If a `2 kg` object is constantly accelerated from `0m/s` to `16 m/s` over `9 s`, how much power musy be applied at `t= 6`?

Answer 1

The power is `=37.9W`

Explanation:

We apply the equation of motion

`v=u+at`

The initial velocity is `u=0ms^-1`

The final velocity is `v=16ms^-1`

The time is `t=9s`

The acceleration is

`a=(v-u)/t=(16-0)/9=16/9ms^.2`

The velocity at `t=6s` is

`v=0+16/9*6=32/3ms^-1`

According to Newton's Second Law, the force is

`F=ma=2*16/9=32/9N`

The power is

`P=Fv=32/9*32/3=37.9W`